import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class LoopBasics extends JFrame implements ActionListener {
    private final int DISPLAY_WIDTH = 800;
    private final int DISPLAY_HEIGHT = 600;

    private JPanel guiPanel;
    private DisplayPanel display;
    int i;
    int num;
    int locX, locY;
    final int LIMIT=30;
    final int LETTER_SPACE =20;
    final int LETTER_HEIGHT=25;
    final int ROW_GAP=5;
    final int COLUMN_GAP=5;
    final int NUM_ROWS=10;

    public static void main(String[] args) {
        LoopBasics frame = new LoopBasics();
        frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
        frame.setLayout(new BorderLayout());

        frame.initializeVariables();

        frame.setUpGUI();

        frame.pack();
        frame.setVisible(true);
    }

    public void initializeVariables(){

        locX=0;
        locY=20;
    }

    public void setUpGUI() {
        display = new DisplayPanel();
        guiPanel = new JPanel(new FlowLayout());

        add(guiPanel, BorderLayout.SOUTH);
        add(display, BorderLayout.CENTER);

    }

    @Override
    public void actionPerformed(ActionEvent e) {

        display.repaint();
    }

    class DisplayPanel extends JPanel {
        DisplayPanel() {
            setPreferredSize(new Dimension(DISPLAY_WIDTH, DISPLAY_HEIGHT));
            this.setBackground(Color.WHITE);
        }

        public void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2d=(Graphics2D)g;
            g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                    RenderingHints.VALUE_ANTIALIAS_ON);
            //whileTest(g2d);
            forTest(g2d);
        }

        public void whileTest(Graphics2D g2d){
            //modify this so that it will print out 1-100
            //each line will have only 30 numbers
            //hint, this will use if statements and a change in locY
            num=1;
            while(num<=LIMIT){
                num++;
                g2d.drawString(num+", ", locX+num* LETTER_SPACE, locY);

            }
        }

        public void forTest(Graphics2D g2d){
            boolean isTrue=true;
            //modify this so that each number alternates between green and red
            for(int j=1; j<=NUM_ROWS; j++) {
                for (int i = 0; i < LIMIT; i++) {
                    g2d.drawRect(locX + i * (LETTER_SPACE+COLUMN_GAP),
                            locY+(j*(LETTER_HEIGHT+ROW_GAP)), LETTER_SPACE, LETTER_HEIGHT);
                }
            }
        }
    }
}